ios - 没有模糊 View 效果的 UIAlertController 操作表

Question

我正在使用 UIAlertController 进行一些操作。

但我不太喜欢操作组 View 中的模糊 View 效果(请参见下面的屏幕截图)。

我正在尝试消除这种模糊效果。我在网上做了一些研究，但在 UIAlertController 中找不到任何 API 可以消除这种模糊效果。另外，根据他们的苹果文档 here :

The UIAlertController class is intended to be used as-is and does not support subclassing. The view hierarchy for this class is private and must not be modified.

我看到 Instagram 也消除了这种模糊的 View 效果:

我能找到的删除它的唯一方法是通过 UIAlertController 的扩展自己更新 View 层次结构。

extension UIAlertController {
    @discardableResult private func findAndRemoveBlurEffect(currentView: UIView) -> Bool {
        for childView in currentView.subviews {
            if childView is UIVisualEffectView {
                childView.removeFromSuperview()
                return true
            } else if String(describing: type(of: childView.self)) == "_UIInterfaceActionGroupHeaderScrollView" {
                // One background view is broken, we need to make sure it's white.
                if let brokenBackgroundView = childView.superview {
                    // Set broken brackground view to a darker white
                    brokenBackgroundView.backgroundColor = UIColor.colorRGB(red: 235, green: 235, blue: 235, alpha: 1)
                }
            }
            findAndRemoveBlurEffect(currentView: childView)
        }
        return false
    }
}

let actionSheetController = UIAlertController(title: title, message: nil, preferredStyle: .actionSheet)
actionSheetController.view.tintColor = .lightBlue
actionSheetController.removeBlurryView()

这很好用，它消除了我的模糊 View 效果:

我想知道的是...我的解决方案是实现该目标的唯一方法吗？或者我在 Alert Controller 外观上遗漏了什么？ 也许有一种更简洁的方法可以准确地实现该结果？还有其他想法吗？

Answer 1

子类化 UIAlertController 更容易。

想法是在每次调用 viewDidLayoutSubviews 时遍历 View 层次结构，移除 UIVisualEffectView 的效果并更新它们的 backgroundColor:

class AlertController: UIAlertController {

    /// Buttons background color.
    var buttonBackgroundColor: UIColor = .darkGray {
        didSet {
            // Invalidate current colors on change.
            view.setNeedsLayout()
        }
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()

        // Traverse view hierarchy.
        view.allViews.forEach {
            // If there was any non-clear background color, update to custom background.
            if let color = $0.backgroundColor, color != .clear {
                $0.backgroundColor = buttonBackgroundColor
            }
            // If view is UIVisualEffectView, remove it's effect and customise color.
            if let visualEffectView = $0 as? UIVisualEffectView {
                visualEffectView.effect = nil
                visualEffectView.backgroundColor = buttonBackgroundColor
            }
        }

        // Update background color of popoverPresentationController (for iPads).
        popoverPresentationController?.backgroundColor = buttonBackgroundColor
    }

}


extension UIView {

    /// All child subviews in view hierarchy plus self.
    fileprivate var allViews: [UIView] {
        var views = [self]
        subviews.forEach {
            views.append(contentsOf: $0.allViews)
        }

        return views
    }

}

用法:

1. 创建警报 Controller 。
2. 设置按钮背景颜色: alertController.buttonBackgroundColor = .darkGray
3. 自定义并呈现 Controller 。

结果: